This work aims to study the toxicity and joint action of the bo-tanical insecticide Neemazal W (powder contains 10% Azadirachtin) with malathion against the cowpea weevil, Callosobruchus maculatus F. Results concerning the toxic effect of neemazal to Cmaculatus adults showed that mortality percentages were proportionally increased with the concentration and exposure time. After 7 days from exposure, mor‌tality values were 68.2, 77.3, 88.9, 100 and 100% at 50, 100, 250, 500 and 1000 ppm, respectively. In comparison, malathion 1% powder induced complete kill at its recommended dose after 3 days from treat‌ment. Mortality values resulted from Katel Sous were 55.6% and 83.1% after 3 and 7 days post treatment, respectively. At the highest concen‌tration of neemazal,F1 progeny of the insect was inhibited by 90.1%. Co-toxicity resulted from addition of the LC50 of malathion to neemazal indicated an additive effect with this insect species at all concentrations tested. Meanwhile, neemazal showed significant reduction in the total number of eggs laid per female, reduced significantly the hatchability of the eggs at high concentration and did not affect significantly the emer‌gence of the adults in comparison with the control. Furthermore, the application of neemazal at the highest concen‌tration, reduced the loss in weight of cowpea from 16.4% to 1.2% after two months from treatment. Consequently, it could be recommended to use the botanical insecticide neemazal alone/or in combination with mal‌athion to protect cowpea from infestion by Canaculatus in frame of an integrated pest management system.